Design and characterization of a new irreversible responsive PARACEST MRI contrast agent that detects nitric oxide
Open Access
- 28 November 2007
- journal article
- research article
- Published by Wiley in Magnetic Resonance in Medicine
- Vol. 58 (6), 1249-1256
- https://doi.org/10.1002/mrm.21428
Abstract
Irreversible responsive PARAmagnetic Chemical Exchange Saturation Transfer (PARACEST) MRI contrast agents constitute a new type of agent for molecular imaging. To investigate the utility of this approach, a novel PARACEST MRI contrast agent, Yb(III)-(1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid)-orthoaminoanilide (Yb-DO3A-oAA), was developed that detects nitric oxide (NO). The agent exhibited two CEST effects at −11 ppm and +8 ppm, which were assigned to chemical exchange from amide and amine functional groups, respectively. The effects of pH, temperature, and concentration were investigated to characterize the complex and to optimize PARACEST detection. This responsive PARACEST MRI contrast agent incurred an irreversible covalent change in the presence of NO and O2, which caused an irreversible disappearance of both PARACEST effects from MR images. The NO-dependent response of a relaxivity-based MRI contrast agent, Gd-DO3A-oAA, was investigated for comparison. This report highlights the advantages of irreversible MRI contrast agents, demonstrates that large changes in PARACEST can be used to create a highly responsive agent, and indicates challenges that must be overcome to apply this type of contrast agent to in vivo biomedical applications in molecular imaging. Magn Reson Med, 2007.Keywords
This publication has 37 references indexed in Scilit:
- Amplification strategies in MR imaging: Activation and accumulation of sensing contrast agents (SCAs)Journal of Magnetic Resonance Imaging, 2006
- A responsive MRI contrast agent to monitor functional cell statusNeuroImage, 2006
- Dendrimer-Based Nanoprobe for Dual Modality Magnetic Resonance and Fluorescence ImagingNano Letters, 2006
- Kinetic analysis of hyaluronidase activity using a bioactive MRI contrast agentContrast Media & Molecular Imaging, 2006
- Supramolecular Adducts between Poly‐L‐arginine and [TmIIIdotp]: A Route to Sensitivity‐Enhanced Magnetic Resonance Imaging–Chemical Exchange Saturation Transfer AgentsAngewandte Chemie-International Edition, 2003
- PARACEST Agents: Modulating MRI Contrast via Water Proton ExchangeAccounts of Chemical Research, 2003
- Magnetic relaxation switches capable of sensing molecular interactionsNature Biotechnology, 2002
- Reactions of Nitric Oxide with Amines in the Presence of DioxygenTetrahedron Letters, 1995
- Nitric Oxide Synthases: Properties and Catalytic MechanismAnnual Review of Physiology, 1995
- Kinetic studies of hydrogen-bonded solvation complexes of amines in water and hydroxylic solventsAccounts of Chemical Research, 1971